Power drive attachment for drilling machine



July 21, 1959 F. H. MUELLER ETAL 2,895,352

POWER DRIVE ATTACHMENT FOR DRILLING MACHINE Filed June 20, 1958 4 Sheets-Sheet I I I PH- I I II i III I l l I I I i 12 i I I \INVENTORS:

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July 21, 1959 F. H. MUELLER ETAL POWER DRIVE ATTACHMENT FOR DRILLING MACHINE Filed June 20, 1958 4 Sheets-Sheet 2 INVENTORS:

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July 21, 1959 F. H. MUELLER ETAL 2,895,352 I v PQWER DRIVE ATTACHMENT F OR DRILLING MACHINE I Filed June 20, 1958 4 Sheets-Sheet 4 14 .UEIC" H I I W025: Fmnkaimwwfi John lsmii'h,

ATTORNEYS.

United States Patent POWER DRIVE ATTACHMENT FOR DRILLING MACHINE Frank H. Mueller and John J. Smith, Decatur, 11]., assiguors to Mueller Co., Decatur, 111., a corporation of Illinois Application June 20, 1958, Serial No. 743,318

7 Claims. (Cl. 77-344) This invention relates to power drive attachments for enclosed drilling and tapping machines of the type employed to drill an opening in the wall of a fluid chamber, such as a water or gas main, thread the opening, and screw into the tapped opening a fitting, such as a valve body or a service T for connecting a branch line to the fluid chamber, all without the escape of pressure fluid from the chamber to atmosphere. More particularly, this invention pertains to improvements in a power drive attachment of the type disclosed in our copending application Serial No. 622,470, filed November 15, 1956.

The power drive attachment disclosed in the aforementioned copending application is adapted primarily to operate a drilling machine by a motor to both rotate the boring bar of the machine and feed the bar at a rate appropriate for a drilling operation. The attachment is not adapted, however, to provide a power drive for a drilling machine during a threading or tapping operation, without first removing the attachment from the machine and making certain adjustments to the latter. As a result, after a hole has been drilled in a main, an operator must remove the power drive attachment from the drilling machine and either employ a manuallyoperable ratchet wrench, or the like, to turn the boring bar of the drilling machine to perform the threading or tapping operation, or make an adjustment to the machine and then re-attach the attachment to perform the tapping operation by power. Obviously, such changeover from power d-Iive drilling to manual or power drive tapping, not only is time-consuming and thus lengthens the time required to perform the entire operation on a main but also is somewhat fatiguing to an operator.

Accordingly, it is an object of this invention to provide an improved power drive attachment for an enclosed drilling and tapping machine, which attachment can be employed for uninterrupted drilling and tapping operations without removal from the machine.

It is another object of this invention to provide an improved power drive attachment of the type under consideration wherein the changeover from drilling to tapping operations can be accomplished readily and rapidly without removing the attachment from a drilling machine.

Other objects and advantages of the invention will become apparent from the following description and accompanying drawings in which:

Figure 1 is an elevational view, partially in vertical section, showing a power drive attachment embodying this invention operatively engaged with a drilling machine that is mounted on a main in position to drill and tap a hole therein.

Figure 2 is an enlarged fragmentary vertical sectional view of a portion of Figure 1 illustrating the interior construction of the power drive attachment.

Figure 3 is an enlarged fragmentary view of the under side of the power drive attachment shown in Figure 1,

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with such attachment being removed from the machine.

Figure 4 is an enlarged fragmentary side view of the power drive attachment shown in Figure 1, taken from the left-hand side of the latter figure.

Figure 5 is a fragmentary side view of the power drive attachment shown in Figure 1 taken from the righthand side of the latter figure.

Figure 6 is a view cor-responding to Figure 1 but showing the position of the parts at the completion of a drilling operation.

Figure 7 is a view corresponding to Figure 1 but showing the position of the parts on the initiation of a tapping operation.

Referring now to the drawings, there is shown in Figures 1, 6 and 7 a portion of a pipe, such as a gas or water main Ill, having mounted thereon a drilling machine 12 provided with a power drive attachment 14 embodying this invention. The machine has the usual barrel 16 Which'includes a cylinder 18 threadedly engaged with a flop valve housing 20, the latter having an open lower end seated on the usual saddle 22 that fits on the main 10. Within the housing 20 is the usual flop valve 24 which cooperates with a valve seat 26 to close off the interior of the housing from that of the cylinder. The barrel 16 is held in position on the main 10 by a chain (not shown) which extends about the main and has its opposite ends secured to forks (not shown) on opposite sides of a chain yoke collar 281 that surrounds the barrel and rests against the upper end of the flop valve housing 20, as best shown in the aforementioned copending application. The upper end of the cylinder 18 is closed by a threaded bonnet or cap 30 provided with radial handles 32 to facilitate its attachment and detachment to and from the cylinder. Thus, the barrel 16 and cap 30 form an interior fluid chamber 34.

Projecting upwardly from the top of the cap 30 is a cylindrical extension 36 of reduced diameter provided with exterior feed threads 38. Sealingly extending coaxially through the cap 30, and its extension 36, is an axially and rotatably movable tubular boring bar 40. The upper exterior end portion 42 of the boring bar 40 is square, or of other non-circular configuration, as shown in Figure 2, and for a short distance below such square end portion, the boring bar is reduced in diameter to provide an upwardly facing shoulder against which is seated a thrust collar 44.

A generally U-shaped yoke 46 has the ends of its legs or arms 48 pivotally carried by a feed collar 50 engaged with the feed threads 38 on the cap extension 36. The collar 50 preferably is provided with radical handles 52 to facilitate its manual rotation. The base 54 of the yoke 46 has a generally U-shaped notch 56 therein, so that the yoke may be swung up in the position shown in Figures 1, 2 and 6, wherein the boring bar 40 is received in such notch and the base of the yoke may bear against the top of the thrust collar 44. In such position, a feeding movement may be imparted to the bar 40 by rotation of the feed collar 50. The yoke 46 preferably is provided with a spring-pressed detent 58 that projects from one side of the notch 56 in spaced relation to the bottom thereof in position to engage the bar 40 and yieldingly retain the yoke in operative position with relation to the thrust collar 44 on the bar. The base 54 of the yoke 46 also is provided with a square, or other non-circularly shaped, extension 60 which is disposed about the notch 56 and extends upwardly from the yoke base, as illustrated in greater detail in the aforementioned application.

The lower or forward end of the boring bar 40 has an enlarged tool holder 62 secured thereto, as by welding, for removably carrying a tool, such as a combined drill and tap 64 having a forward drilling portion 66 followed by a tapping portion 68 and a tapered shank 70, as shown in Figure 1. The holder 62 is provided with a tapered socket 72 for receiving the tool shank 70 and with diametrically-opposite notches 74 in the rim of the socket for reception of the projecting ends of a transverse driving pin 76 in the tool shank. The end of the tool shank '70 preferably is provided with a coaxial threaded socket engageable by the lower threaded end of a draw rod 78 to retain the tool 64 in the holder 62. The rod 78 extends rearwardly completely through the boring bar 40 and is provided at its upper exterior end with an enlarged noncircular head 80 engageable by an appropriate turning tool, such as a wrench (not shown), as shown in greater detail in the previously mentioned application.

The power drive attachment 14 embodying this invention includes a housing 82 having a somewhat dish-shaped main body 84 and a top covers 86, which may be secured to the body by screws 88 extending through flanged peripheries of the cover and body. lournalled in a hearing portion of the cover 86 and projecting into the housing 82 is a drive shaft having a square, or other appropriate non-circular, socket 92 in its outer end for 116 apart.

driven engagement by the complementary end of the driving shaft of a suitable prime mover, such as an air or an electric motor (not shown). The outer end of the shaft 90, adjacent the socket 92, is exteriorly threaded for the reception of a split clamping nut 93, while the other end of the shaft 90 projects through a bearing portion of the body 84 and is enlarged, as at 94, to form a shoulder 96 thereon facing the inner side of the cover 86. Formed in the end of the enlarged shaft portion 94 is a socket 98 that is exposed to the exterior of the housing 82 and is of substantially the same length as and complementary to the non-circular end portion 42 of the boring bar 40 for driving engagement therewith. The bottom of the socket 98 is provided with a central circular recess or socket 100 for non-driving accommodation of the rod head 80.

Journalled in the bearing portion of the body 84 is a tubular yoke-driving sleeve 102 that is rotatably mounted on the enlarged portion 94 of the shaft 90 and has an interior circumferential flange 104 at its inner end which overlies the shoulder 96 on the shaft. Preferably a hearing bushing 106 is interposed between the sleeve 102 and the shaft 90 in order to facilitate free relative rotation therebetween. The outer end 108 of the sleeve 102, which is flanged and offset slightly rearwardly of the corresponding outer end of the shaft 90, is provided, on one side, with a radial enlargement or extension 110. The extension 110 may be secured to the sleeve outer end 108 by welding. Carried by the radial sleeve enlargement 110 is a forwardly projecting combined driving and pivot pin 112 that may be secured to the enlargement by extension into a bore therein where it is retained by a longitudinally-split locking pin 114 extending, with a drive fit, transversely through the enlargement and the pin 112.

Pivotally mounted on the pin 112 are two angular arms 116 adapted to drivingly embrace the square extension 60 on the yoke 46. Essentially, these arms 116 form a split socket complementary to and for driving reception of the yoke extension 60, as best shown in Figure 3. The arms 116 are retained on therpin 112 by a head 118 on the latter, while the free ends of the arms 116 are provided with notches or slots 120, best shown in Figure 5. Extending transversely through the free end of one of the arms, and through the notch 120 therein is a pivot pin 122 on which is mounted an eye bolt 124 having a threaded shank 126 adapted to be swung into and out of the unobstructed notch 120 in the other arm 116. A wing nut 128, and a washer 130, are mounted 011 the bolt 124 so that when the latter is swung into the unobstructed notch 120 in the other arm 116, the nut can be tightened to bear against the outer side of the arm and retain the two arms in position to form the aforedescribed split socket. It will be seen that the nut 128 readily can be unscrewed,

, f4 however, and the bolt 124 swung out of the unobstructed notch 120, so that the two arms 116 can be swung apart to free them of driving engagement with the yoke extension 60.

In order to rapidly accomplish the aforedescribed separating movement of the arms 116, a recess is formed therebetween about the pivot pin 112 and a coil torsion spring 134 is disposed in the recess about the pin 112. The opposite ends of the spring 134 are extended to form arms 136 having right-angled ends 138 engaged in openings in lateral lugs 140 on the two arms 116. The spring 134 is placed under an initial stress when assembled in place so that it constantly urges the two arms Accordingly, when the bolt 124 is swung into an arm-disconnecting position, the spring 134 rapidly separates the two arms 116 to free them of their driving engagement with the yoke extension 60.

Preferably, a stop 142, which may be a longitudinallysplit pin that has a drive fit in an opening in the enlargement 110 parallel to the pivot pin 112, is positioned to be engaged by the two arms 116 to limit their separating movement. Additionally, the sleeve outer end 108 is provided, at diametrically opposite locations, with forwardly extending stops 144, that again may be longitudinallysplit pins having a drive fit in apertures in the sleeve end 108, positioned to engage with the inner corners 146 of the arms 116 so that the latter cannot be brought so close together that they cannot receive the square projection 60 on the yoke 46, as shown in Figure 3.

Within the housing 82 a large gear 148 is mounted on the sleeve 102 and secured thereto, as by a key 150, with one side of its hub portion bearing against the inner surface of the housing body 84. A smaller gear 152 is secured to the shaft 90 within the housing 82, as by a key 154, and at one side bears against the inner surface of the cover 86. interposed between the inner end of the sleeve 102 and the gear 152 is a spacer Washer 156 which also overlies and bears against the hub portion of the gear 148. From the foregoing construction, it will be seen that the clamp nut 93, together with the gears 148 and 152, spacer washer 156, and sleeve flange 104, serves to retain the shaft and the sleeve 102 against axial movement relative to the housing 82, while the housing body 84 and the spacer washer 156 likewise retain the gear 148 against such movement.

Journalled in appropriate, aligned bearing sockets 160 and 162 formed in the interior surfaces of the cover 86 and the body 84, respectively, is an idler shaft 164 offset from the drive shaft 90. A small gear 166 integral with the shaft 164 meshes with the large gear 148. A larger gear 168 is secured to the shaft 164, as by a key 170, and has the opposite sides of its hub portion bearing against the interior surface of the cover 86 and a shoulder 172 on the idler shaft 164, respectively. From the foregoing construction, it will be seen that the gears 148, 152, 166 and 168 constitute a reduction drive for driving the sleeve 102 at a speed less than, that of the shaft 90. The gear ratios are such that when the attachment 14 is in use, as later described, the boring bar 40 will be fed at a rate appropriate for a drilling operation.

On the upper side of the cover 86 is an upstanding lug 174 provided with a transverse bore for the reception of a pivot pin 176 that can be retained in place by a thumb screw 178. This arrangement may serve to pivotally support a motor holder 180 (shown in dot-dash lines) on the attachment 14. The upper side of the cover 86 also preferably is provided with an eye bolt 182 mounted on a pivot pin 184 carried by a pair of upstanding lugs.

186 on the cover. The eye bolt 182 is provided vw'th a Wing nut 188, so that when the bolt is swung up into a notch in the edge of the holder 180, the nut can be tightened to retain the holder in operative position. The motor holder 180 may be of the type illustrated, for example in US Patent No. 2,651,222, and in general serves to properly position and hold a motor (not shown),

3 which may be either air or electric, in position for driving engagement with the outer end of the shaft 20.

In use, the attachment 14 is positioned on top of the boring bar 40, with the yoke 46 in its feeding position, and manipulated until the upper square end portion 42 of the bar is received in the socket 92 of the attachment. The yoke 46 is then rotated, as by the handles 52 on the feed collar 54), until the two arms 116 can be brought together and locked by the eye bolt 124 and wing nut 128, to define a socket which drivingly receives the square extension 60 on the base 54 of the yoke 46. The motor holder 180 and its motor (not shown) then can be fastened to the attachment 14, and the motor can be operated to drive the shaft 90 to thereupon drive the boring bar 40 to drill a hole in a main. At the same time, it will be seen that the yoke 46 will be driven at a rate of rotation less than that of the boring bar 4th to feed the latter automatically at a rate appropriate for a drilling operation.

As soon as the drilling portion 66 of the tool 64 completely penetrates through the main 10, as shown in Figure 6, and which penetration can readily be determined by an operator, by sensing a decrease in the load on the driving motor, the Wing nut 128 is unscrewed and the eye bolt 124 swung out of the unobstructed notch 120 in the end of one of the arms 116 so that the spring 134 Will separate the arms 116 and disengage the drive between the attachment 14 and the extension 60 on the yoke 46. Consequently, the boring bar 40 will continue to be driven while an operator may rapidly rotate the feed collar 50, by the handles 52, to rapidly feed the boring bar forwardly until the tapping portion 68 of the tool 64 is operatively engaged with the drilled hole in the main 10, as shown in Figure 7. The boring bar 40 can then be continued to be driven by the power drive attachment 14, and its driving motor, so that the tapping operation can proceed by power. After once being initiated, how ever, a tapping operation is, more or less, self-feeding. Hence, after the tapping operation has progressed a short distance, the yoke 46 can be swung out of engagement from over the top of the thrust collar 44 on the boring bar, as shown in Figure 7, so as not to interfere with downward movement of the power drive attachment 14 during the tapping operation. In this connection, while it will be realized that such interference could be avoided by rotating the feed collar 50 by hand to feed the yoke 46 downward, it will be much simpler to obviate any possibility of interference by swinging the yoke 46 out of the way, as shown in Figure 7.

After the tapping operation has been completed, the motor is reversed to rotate the boring bar in a direction to unscrew the tool 64 from the tapped opening in the main.

It thus will be seen that the objects of this invention have been fully and effectively accomplished. It will be realized, however, that the foregoing specific embodiment has been shown and described only for the purpose of illustrating the principles of this invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.

We claim:

1. A power drive and automatic feed attachment for use with a drilling machine having a boring bar provided with a driving end, a feed collar concentric with the bar and threadedly engaged with a fixed part of the machine, and a feed yoke pivotally connected to the collar and swingable into and out of engagement with a shoulder on the bar to feed the latter, when engaged with the shoulder, by rotation of the collar, the combination comprising: a housing; a bar-driving member journalled in said housing and having noncircular means exposed exteriorly of said housing for driving engagement with complementary means on the driving end of the bar; a tubular yoke-driving member journalled in said housing concentrically about said bar-driving member and having a portion projecting outwardly of said housing for driving engagement with the yoke; movable means on said portion for disengaging the last-mentioned driving engagement while maintaining the first-mentioned driving engagement; a shaft means having an end accessible from the exterior of the housing for driven engagement by exterior driving means and connected to said bar-driving member for driving the latter; and gear means journalled in said housing and connecting said shaft means with said yoke-driving member to drive the latter by the former.

2. The structure defined in claim 1 in which the portion on the yoke-driving member comprises a non-circular split socket adapted to drivingly receive a complementary portion on the yoke.

3. The structure defined in claim 2 in which the socket is formed by two parts pivotally connected together for separating movement away from the yoke portion, and including disconnectable means for connecting the two parts together at their separating edges.

4. The structure defined in claim 3 including spring means engaged with the two parts for constantly urging them to separate.

5. A power drive and automatic feed attachment for use with a drilling machine having a boring oar provided with a driving end, a feed collar concentric with the bar and threadedly engaged with a fixed part of the machine, and a feed yoke pivotally connected to the collar and swingable into and out of engagement with a shoulder on the bar to feed the latter, when engaged with the shoulder, by rotation of the collar, the combination comprising: a housing; a bar-driving member journalled in said housing and having a non-circular socket exposed exteriorly of said housing for driving reception of a complementary portion of the driving end of the bar; a tubular yokedriving member journalled in said housing concentrically about said bar-driving member and having a portion projecting exteriorly of said housing; a pair of angular arms adapted to drivingly embrace a non-circular portion of the feed yoke; means pivotally connecting a pair of adjacent ends of said arms to each other and to said exterior portion of said yoke-driving member at a location offset from the axis of rotation of the latter; means for detachably connecting the other ends of said arms togcther in position to drivingly embrace the yoke portion; means accessible from the exterior of said housing for detachably connecting a driving motor to the attachment to drive said bar-driving member; and gear means in said housing connecting said bar-driving member with said yoke-driving member for driving the latter by rotation of the former.

6. The structure defined in claim 5 in which the means for detachably connecting the other arm ends together comprises a bolt pivotally connected to one arm end and swingable into and out of a slot in the other arm end.

7. The structure defined in claim 5 including spring means engaged with the arms to constantly urge them apart.

References Cited in the file of this patent UNITED STATES PATENTS 2,640,377 Millholland June 2, 1953 2,646,699 Mueller et a1. July 28, 1953 2,679,173 Hill May 25, 1954 2,838,964 Albertson et a1. June 17, 1958 

